(1) Field of the Invention
The invention relates to beams that support attached drywall sheets to form suspended drywall ceilings and ceiling soffits.
(2) Description of the Related Art
Beams used in suspended drywall ceilings are well known. In such ceilings, beams are suspended by hanger wires from a structural ceiling, and sheets of drywall are secured to the suspended beams by self-tapping screws.
The beams are made by continuously rollforming a strip of metal to fold the strip longitudinally into an inverted T cross section, with a bulb at the top, a web extending down from the bulb, and two flanges extending horizontally opposite from one another at the lower end of the web. The flanges have indentations over their lower surface that capture self-tapping screws to permit the screws to penetrate the flange after passing through the drywall sheet.
Such a beam is shown, for instance, in U.S. Pat. No. 6,722,098, for Beam for Drywall Ceiling, incorporated herein by reference.
Suspended drywall ceilings generally extend horizontally. Occasionally, a ceiling soffit in the form of an underhang, having a two dimensional cross-section, is formed. The drywall ceiling soffit is made with the same kind of beams and drywall sheets used in a horizontal drywall suspended ceiling. In forming the soffit, straight beams of the kind used in such horizontal drywall suspended ceiling are individually cut and bent in the field, and fastened together by drilling holes and inserting fastening screws. A plurality of bent beams is used to form a beam framework for the soffit.
Such work in the field is time-consuming, and often non-uniform, so that the parts do not fit well together.